Yaounde , Cameroon -LRB- CNN -RRB- -- French military and intelligence officers have entered northern Cameroon in search of a family of seven French tourists kidnapped Tuesday from a national park , a CNN affiliate reported Wednesday .

The Paris-based private network BFMTV did not cite its source ; it posted a team of journalists Wednesday in Paris at the French Foreign Ministry Crisis Center , which is handling the country 's response to the crisis .

BFMTV , citing the French Defense Ministry , said gendarmes had been sent to the site in northern Cameroon where the abduction occurred to investigate .

But a Cameroonian official said Wednesday that he believed the family had been taken across the border into neighboring Nigeria within hours of their abduction .

Joseph Dion Ngute , the Foreign Ministry official in charge of ties with Commonwealth nations , said Tuesday 's incident marked the first time foreigners in Cameroon had been taken captive by suspected Islamic militants of Nigeria 's Boko Haram movement .

`` The intentions of the kidnappers are yet to be known , '' he said .

French officials blamed the incident on Boko Haram , which has taken advantage of Nigeria 's porous borders with Chad and Cameroon in its three-year campaign .

Boko Haram has waged a war against Nigeria 's government and its Christian population in an effort to establish a strict Islamic state in northern Nigeria .

The family was kidnapped from Waza National Park , a thickly forested area of northern Cameroon popular among tourists and located near the border with Nigeria . The incident has raised fears of Westerners being targeted by Islamist militant groups in Africa in the wake of France 's military intervention in Mali .

But French President Francois Hollande said Tuesday that he did n't believe the seizure was linked to his government 's intervention in Mali , where French troops have joined government forces to battle Islamic militants linked to al Qaeda .

`` I am aware of the presence of Boko Haram in that part of Cameroon , and that 's worrying enough , '' Hollande said .

The abductees include four children ages 5 to 12 , their parents and an uncle , the Cameroon 's state broadcaster CRTV reported .

Fonkam Azu , governor Cameroon 's northern region of Maroua , told reporters that residents saw the hostages being driven into Nigeria on motorcycles .

The father works for the French company GDF Suez and is based in Yaounde , the capital in southern Cameroon . GDF Suez , which is developing a natural gas liquefaction project in Cameroon , said it was working closely with the French Foreign Ministry .

Concerns about border security in northern Cameroon grew early last year , when Sudanese poachers on horseback invaded the Bouba Ndjida Park and killed more than 300 elephants for their ivory . Afterward , the government temporarily replaced park guards with a special anti-terrorist squad of the military .

In a statement , Cameroon 's Ministry of External Relations said Wednesday that security has been tightened to guarantee the safety of expatriates and tourists , especially in volatile regions .

Abductions are common in Cameroon , especially in natural resource-rich regions .

In January , kidnappers killed one Chinese national and abducted three others from the Betare Oya gold mine in the country 's south . The military freed the surviving hostages . And several abductions targeting foreigners have occurred in the oil-rich Bakassi Peninsula , on the country 's Atlantic coast .

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NEW : French gendarmes have been sent to the abduction site , CNN affiliate reports

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France and Cameroon suspect the Nigerian militant group Boko Haram

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The kidnapping raises fears of retaliation for French military action in Mali